Developmental changes from birth through adolescence may have a profound impact on drug disposition as drug metabolism and elimination differ in children versus adults. Nevertheless, there is a paucity of Food and Drug Administration approved labeling for drugs in newborns, children, and adolescents. As a consequence, drug dosing for children is often based on the results of pharmacologic studies performed in adults. This practice is inappropriate and may place children at risk of undesirable consequences including severe or unacceptable toxicities or even lack of drug efficacy. To improve the safety and efficacy of both new and commercially available drugs for children of all age groups, increased collaboration between academia and industry is required. A primary focus of such a cooperative program should be to develop studies that are specifically designed to evaluate drug action and disposition in the pediatric patient population. Such studies are best performed in the context of a well-established cooperative group such as the network of Pediatric Pharmacology Research Units (PPRU). The Clinical Pharmacology Group (CPG) at Texas Children's Hospital(TCH)/Baylor College of Medicine (BCM) was established to provide preclinical and clinical pharmacology support for pediatric drug studies performed throughout the different pediatric sub-specialties. It includes board certified pediatricians, clinical pharmacologists, postdoctoral fellows, clinical research nurses, pharmacists, data managers, and research assistants. The CPG consists of a core pharmacology laboratory and a comprehensive, integrated clinical trial research infrastructure and functions as the equivalent of a PPRU. Studies performed by the CPG in the pediatric population include those designed to evaluate drug metabolism, pharmacokinetics, pharmacodynamics, and the safety and efficacy of both commercially available and investigational drugs. An important focus of the CPG is to conduct preclinical and clinical studies aimed at increasing understanding of those developmental characteristics that affect drug disposition and metabolism in children. The TCH/BCM NIH funded General Clinical Research Center provides support for many CPG clinical studies. The CPG has significant experience performing single institution, multi- institutional, and national cooperative group Phase I, II and III clinical trials. In addition, the CPG has an established training program in which a variety of pediatric health professionals receive a supervised training experience in preclinical and clinical pediatric pharmacology.